If used occasionally, Ivory soap does not kill St. Augustine grass. Texas A&M University found that Ivory soap used as an insecticidal soap was effective in controlling some lawn pests without significantly damaging the grass. Repeated applications, however, can harm grass over an extended period of time.
About this Author
Lisha Smith writes for several blogs and has freelanced for six years. She has a Bachelor of Arts from UNC-Greensboro in psychology. Smith has self-published several books. Her areas of experience include gardening, cooking, home improvement, pets and mental health.